[GHC] #12510: GHC.Prim.~# shows up unexpectedly in a pattern synonym type

[GHC]

#12510: GHC.Prim.~# shows up unexpectedly in a pattern synonym type
-------------------------------------+-------------------------------------
           Reporter:  goldfire       |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 When I load

 {{{
 data T a where
   MkT :: Bool -> T Bool

 pattern P x <- MkT x
 }}}

 into GHCi and ask `:info P`, I get

 {{{
 pattern P :: () => t GHC.Prim.~# Bool => Bool -> T t
 }}}

 That should say `t ~ Bool` without `-fprint-equality-relations`.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12510>
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